Stackable energy transfer core spacer

ABSTRACT

A stackable spacer element for use in a energy recovery core formed by stacking a plurality of relatively thin energy transfer media (e.g. sheets, panels, or plates (un-perforated exchanger sheets) so as to define a plurality of stacked energy transfer stages providing air passages for two separate air flows.

The present application is a division of patent application Ser. No.10/739,412 filed on Dec. 19, 2003. The entire content of said U.S.application Ser. No. 10/739,412 is herein incorporated by reference.

This invention relates to an energy transfer element or stage which maybe employed in an energy recovery core incorporated in an airconditioning system and a method of making such an energy transferelement or stage.

The present invention in particular relates to a stackable spacerelement for use in an energy recovery core formed by stacking aplurality of relatively thin heat transfer media (e.g. sheets, panels,or plates (i.e. un-perforated exchanger sheets)) so as to define aplurality of stacked energy transfer stages providing air passages fortwo separate air flows, e.g. one for outside fresh air and one for staleinterior air from an enclosure i.e. room of a building such as a house.The so formed energy recovery core may for example be used to transferheat from discharged interior air to fresh atmospheric air. Thus forexample the present invention relates to a heat recovery core of thecross-flow type, namely of the type wherein core air passages aredisposed transverse (e.g. perpendicular) to each other in an interleavedfashion i.e. one passageway being transverse to the immediately adjacentpassageway (or at least parts thereof). A suitably configured frameassembly may as desired or necessary be provided in contact with thebottom exchanger stage and the top exchanger stage for holding theplurality of stages in position as by a clamping type action.

Stacked type heat exchange cores are known for transferring heat betweensupplied atmospheric air and discharged interior air without allowingthem to mix with each other; see for example U.S. Pat. Nos. 5,832,993and 5,181,562. It is known that energy recovery cores may be of twotypes, namely cross flow cores and counter flow cores.

For cross flow cores it is known for example to use a corrugated boardtype heat exchanger in an air conditioning system or the like. In orderto make such an exchanger, generally rectangular heat exchanging papersheets and corrugated partitions are alternately stacked one on top ofthe other. The heat-exchange paper sheets and the corrugated partitionsare also bonded to each other to preventing air from mixing betweenadjacent air passages. The directions of the partitions on oppositesides of a paper sheet are disposed so as to be oriented at right anglesto each other such that two perpendicular air flow passages oftriangular cross section are provided. Heat exchange is performedbetween air flowing through these air flow passages.

It is also known to provide an exchanger core made up of a plurality ofheat exchange elements each of which comprises a heat exchanging papersheet and a plurality of parallel vertically extending partition piecesformed from a synthetic resin. The partition pieces are verticallymounted on one side of the paper sheet; the synthetic resin partitionpieces are formed integrally with the paper sheet. A large number ofsuch heat exchange elements are stacked so that the direction of thepartition pieces of each heat exchange element are alternately changedby 90 degrees. In this construction, each air flow passage has arectangular cross section, which can reduce the air flow pressure lossas compared with the above-described corrugated core structure. However,producing the above-described heat exchange elements requires specialproduction equipment and forming dies, resulting in relatively highproduction costs for this type of the heat exchange element. It would beadvantageous to have an energy recovery element able to facilitate themanufacture of an energy recovery core for effective transfer of heatbetween fluids ((e.g. such as air) flowing through an energy recoverydevice. It would also be advantageous to be able to assemble an energyrecovery core using self positioning spacer members. It would further beadvantageous to be able to provide a peripheral energy transfer corespacer or use in the construction of an energy recovery core comprisinga core stack comprising alternate layers of an energy transfer media ofrelatively thin material (e.g. sheets, plates, or the like) and spacermembers. It would further be advantageous if a such energy transfermedia and spacers could be stacked in successive, if so desiredadhesive-less, layers so as to define a core. It would also beadvantageous if the spacers could be provided with tongue/mortiseaspects for interlocking adjacent spacers together.

STATEMENT OF INVENTION

Thus the present invention provides a stackable energy transfer corespacer comprising a peripheral frame member,

-   -   said peripheral frame member extending about and defining a        framed core opening,    -   said peripheral frame member having a pair of opposed major        sides,    -   said peripheral frame member comprising        -   a pair of side opening components and        -   a pair of side wall components,    -   each side opening component comprising a framed side opening in        fluid (i.e. air) communication with said framed core opening,    -   each side wall component respectively interconnecting said side        opening components, said spacer being configured such that said        spacer may be oriented and stacked, major side to major side, on        top of a second like spacer, with an intermediate air to air        energy transfer or exchanger sheet extending across (i.e.        covering) the framed core openings and being sandwiched between        the frame members of both spacers so that the spacers and the        energy transfer sheet define a pair of transversely oriented        (i.e. non-parallel) fluid (i.e. air) paths on opposite sides of        the energy transfer sheet, each fluid (i.e. air) path extending        from one respective framed side opening through a respective        framed core opening to the other respective framed side opening        of a respective spacer.

The present invention further provides a fluid to fluid (e.g. an air toair) energy recovery core having a first fluid (e.g. air) path and aseparate second fluid (e.g. air) path, each fluid (e.g. air) path havinga respective fluid (e.g. air) inlet and a respective fluid (e.g. air)outlet, said core comprising a stack of one or more successive energytransfer stages, each such stage comprising an energy transfer sheethaving opposed major faces and a pair of spacers engaging opposite majorfaces of the sheet, each of said spacers being a spacer as definedherein, said spacers being oriented and disposed relative to each otherso that the spacers and the energy transfer sheet define a pair oftransversely oriented fluid (i.e. air) paths on opposite sides of theenergy transfer sheet, each fluid (i.e. air) path extending from onerespective framed side opening through a respective framed core openingto the other respective framed side opening of a respective spacer, theframed side openings of one frame member each respectively defining arespective element of the fluid (e.g. air) inlet and fluid (e.g. air)outlet of the first fluid (e.g. air) path and the framed side openingsof the other frame member each respectively defining a respectiveelement of the fluid (e.g. air) inlet and fluid (e.g. air) outlet of thesecond fluid (e.g. air) path.

In accordance with the present invention a stackable energy transfercore spacer may comprise a peripheral frame member wherein, on eachmajor side thereof, the peripheral frame member comprises aninter-registrable tongue/mortise interlock element. In accordance withthe present invention a frame member may be configured such that whenthe air to air energy transfer sheet is sandwiched between said framemember and the frame member of a second like spacer, the air to airenergy transfer sheet is sandwiched between tongue/mortise interlockelements of said frame member and the frame member of said second likespacer.

In accordance with the present invention a stackable heat transfer corespacer (e.g. frame member thereof) may have a square configuration, ahexagonal configuration, etc.

In accordance with the present invention a spacer may, for example,further comprise, disposed in the framed core opening one or more (e.g.a plurality) elongated channel or rib elements which may as desired ornecessary extend from one first framed side opening to the other, forguiding air between the framed side openings. In the latter case, aframed side opening may thus take on the form of a single opening or becomprised of a plurality of opening units, i.e. if guide rib elementsare present. Alternatively, some or all of the channel or rib elementsmay extend to only one of the framed side openings and/or be disposedentirely within the framed core opening (i.e. not extending to a framedside opening. The channel or rib elements may be configured so as tofacilitate fluid (e.g. air) flow between framed side openings throughthe framed core opening. The channel or rib elements may be connected tothe frame member in any suitable desired or necessary manner. Inaccordance with the present invention the channel or rib air may merelyrest up against the adjacent air to air heat transfer sheet, i.e. theyare not attached to nor integral with the air to air heat transfersheet.

A stackable energy transfer core spacer of the present invention may,for example, be a unitary (e.g. integrally molded) spacer of syntheticresin or plastics material.

A stackable energy transfer core spacer in accordance with the presentinvention may as mentioned above, be used for the construction of anenergy transfer core (e.g. providing alternating cross-flow channels forenergy or heat exchange between two fluid streams) wherein a pluralityof like spacers are stacked in successive layers, with energy transfermedia in the form of sheets or the (e.g. total heat transfer media)sandwiched between adjacent spacers, so as to define an energy transfercore. In other words, in accordance with the present invention an energyrecovery core may thus comprise one or more (e.g. a plurality of)successive energy transfer stages, each such stage comprising an energyor heat transfer media in the form of a sheet (e.g. sheet panel or thelike) and a pair of spacers disposed on opposite major faces of themedia, said spacers comprising a peripheral frame defining a framedopening or space and a pair of peripheral framed edge openingscommunicating with the framed opening space. The framed edge openingsmay, for example, as mentioned herein, be on opposite sides of the framemember, i.e. the frame member may have a square configuration.

As may be understood, the frame member may be configured such that whena like spacer is stacked on top of a like spacer, with a fluid to fluid(e.g. air to air) energy transfer sheet sandwiched therebetween, theframe members of each spacer may engage the periphery of the energytransfer sheet so as to form a partition between the framed core openingof each spacer.

In accordance with the present invention the energy transfer media maysandwiched between the frame members of first and second adjacentspacers so as to define an air tight joints, the air tightness beingprovided by the presence of a suitable adhesive or be inducedmechanically by any suitable clamping type mechanism which forces theopposed spacers to press together to squeeze the heat transfer mediatherebetween.

The spacer may take on any suitable configuration provided that it hasthe requisite side opening and side wall components which allow for anenergy recovery core to be built up from a single spacer configuration,the core having a first inlet interconnected with a first outlet and asecond inlet interconnected with a second outlet. Keeping the above inmind the spacer may have a circular shape; it may have a polygonal shapesuch as a square, hexagon, etc.

If the frame member of a spacer has a square configuration then theframe member may be configured such that when the spacer is oriented 90degrees in its plane with respect to the like spacer and the like spaceris stacked on top of the spacer with heat transfer media therebetweenthe above mentioned air paths are defined by the spacers and heattransfer media on opposite sides of the energy transfer media (seebelow). Alternatively, instead of being rotated a spacer may have to beflipped over 180 degrees with respect to an underlying spacer; see forexample the hexagonal configuration as described below.

The reference to the expressions “energy transfer sheet”, “heatexchanger sheet” or the like is of course, to be understood herein, tobe a reference to a sheet or the like which is non-permeable to fluid(e.g. air) so as to avoid mixing of air on opposite sides of the sheet;similarly with respect to the expression “energy transfer media”.

As mentioned herein a frame member may further comprise on each of theopposite major sides thereof tongue/mortise interlock elements wherein atongue interlock element is able to register with (e.g. in) a mortiseinterlock element so as to interlock adjacent like spacers with a heatexchange sheet panel sandwiched therebetween such that relative lateralmovement (i.e. forward rearward and/or sideward movement) is inhibited.

It is to be understood herein that the word “sheet” in relation to theexpressions “energy transfer sheet”, “energy recovery sheet”, “energyexchanger sheet” and the like is to include panels as well as plates andthe like, i.e. an energy transfer media of relatively thin material(e.g. sheets, plates, or the like).

The energy exchanger or transfer sheet may be of any suitable (known)material able to facilitate sensible heat transfer and if so desired thetransfer of humidity (i.e. water vapor) as well; in other words thesheet may be able to transfer of latent heat as well as sensible heat(i.e. total heat). Such heat transfer media sheets are known and can bemade from numerous different materials, including specially treatedpaper sheets, fiberglass reinforced sheets or any other type suitablefor the application.

It is to be understood herein that a tongue/mortise interlock elementmay comprise a tongue member, a mortise member or both.

It is also to be understood herein that a reference to the expression“inter-registrable tongue/mortise interlock element” as it is applied toa major side of a frame member characterises a “tongue/mortise interlockelement” as being configured to register or be able to register with a“tongue/mortise interlock element” on a major side of the frame memberof another like spacer. In other words the tongue/mortise interlockelements are to be configured such that when an air to air heatexchanger sheet is sandwiched between the frame members of a pair oflike spacers, the tongue/mortise interlock element on the major side ofone spacer is able to register with the tongue/mortise interlock elementon the opposed adjacent major side of the other spacer disposed.

The tongue/mortise interlock elements on opposite major sides of aspacer may take on any desired or necessary configuration. It is,however, to be kept in mind that these elements are to respectivelycooperate with the tongue/mortise interlock elements of like upper orunderlying spacer(s) as the case may be such that when such spacers arestacked together the complementary tongue and mortise elements thereofdefine a pair of interlocked elements able to inhibit lateraldisplacement of the spacers relative to each other. These elements mayalso be exploited for the self alignment of one spacer with respect toanother like spacer.

The upper major side of a spacer may, for example, have a tongue elementformed with a convex part(s) whereas the corresponding mortise elementon the opposite major side may be formed with a complementary concaverecess(es).

The tongue/mortise elements may for example be disposed so as to bespaced apart from the side ends of a spacer, so as to be disposedadjacent one side end or so as to extend from one side end to the otherside end. The tongue/mortise elements of a spacer block may for examplelongitudinally extend along a side of a frame member either completely,partially or intermittently.

The member(s) of the tongue/mortise element of one major side of a framemember may be aligned with the member(s) of the tongue/mortise elementof the other opposite major side of a spacer. Alternatively the opposedmembers may be offset (e.g. outwardly or inwardly) with respect to eachother as, for example, discussed below.

Although like spacers may be provided with tongue/mortise interlockelements on opposite major sides thereof, such spacers may in accordancewith the present invention nevertheless be provided with atongue/mortise elements which are sized and configured relative to eachother so as to permit limited adjustment (i.e. positional adjustment) ofa spacer, i.e. to allow for a minor amount of clearance or play betweenthe tongue/mortise interlock elements.

In drawings which illustrate example embodiments of the presentinvention

FIG. 1 is a schematic illustration of air flow for a cross flow typeenergy recovery core;

FIG. 2 is a schematic illustration of air flow for a counter flow typeenergy recovery core;

FIG. 3 is a schematic perspective view of an example square spacer inaccordance with the present invention;

FIG. 4 is a schematic perspective view of a pair of the example spacersas shown in FIG. 3 in the process of being associated with an air to airenergy transfer sheet (e.g. energy transfer paper);

FIG. 5 is a schematic perspective view of an energy recovery corecomprising a stack of spacers as shown in FIG. 3 and associated air toair heat transfer sheets;

FIG. 6 is a schematic cross section view of an energy exchange orrecovery system incorporating the energy recovery core as shown in FIG.5;

FIG. 7 is a schematic plan view looking down on one major side of anexample configuration of a spacer for incorporation into an energyrecovery core for a hybrid counter/cross air flow through the core;

FIG. 7 a is the same schematic plan view as shown in FIG. 7 but withoutthe dashes outlining triangular zones;

FIG. 7 b is a schematic plan view of the example spacer shown in FIG. 7looking down on the other or opposite major side as shown in FIG. 7(i.e. the flip side);

FIG. 8 is an enlarged schematic illustration of a partial crosssectional view of the peripheral edge of the spacer of FIG. 7 showing anexample configuration for a spacer tongue and corresponding spacergroove for sandwiching therebetween a heat transfer media in place;

FIG. 9 is a schematic plan view of a sheet of an energy transfer mediafor disposition between a pair of spacers as shown in FIG. 7;

FIG. 10 is a schematic perspective view of a plurality of the examplespacers as shown in FIG. 7 in the process of being associated with aplurality of air to air energy transfer sheet (e.g. paper) as shown inFIG. 9;

FIG. 11 illustrates an assembled counter/cross flow core made with theexample spacers as shown in FIG. 7 and the energy transfer media shownin FIG. 9;

FIG. 11 a is a schematic illustration of an example frame assembly forclamping together the components of the counter/cross flow core shown inFIG. 11;

FIG. 12 shows two spacers of FIG. 7 superimposed in stack fashion withthe energy transfer media shown in FIG. 9 removed;

FIG. 13 is a schematic perspective view of an example squareconfiguration of a spacer for incorporation into an energy recovery corefor a cross air flow through the core;

FIG. 13 a is a schematic plan view looking down on one major side of theexample square spacer shown in FIG. 13;

FIG. 13 b is a schematic side view of a side wall component of theexample square spacer shown in FIG. 13;

FIG. 13 c is a schematic side view of a side opening component of theexample square spacer shown in FIG. 13;

FIG. 13 d is a schematic plan view of the example spacer shown in FIG.13 looking down on the other or opposite major side as shown in FIG. 13(i.e. the flip side);

FIG. 14 is a schematic perspective view of a number of square spacers,of another example type, shown in the process of being stacked inassociation with a number of respective air to air energy transfersheets (e.g. paper);

FIG. 15 is an exploded perspective cross sectional view of the energyrecovery core stack as obtained from the process shown in FIG. 14;

FIG. 15 a is an enlarged view of the portion of FIG. 15 designated A;

FIG. 16 is a side view of the cross section shown in FIG. 15;

FIG. 16 a is an enlarged view of the portion of FIG. 15 designated B;

FIG. 17 is an enlarged view of an edge portion of a further examplespacer showing snap means for interlocking adjacent spacers together atthe edge portions thereof; and

FIG. 18 is an enlarged view of an edge portion of another example spacershowing another type of snap means for interlocking adjacent spacerstogether at the edge portions thereof;

FIG. 1 is illustrative of air flow through a cross flow core; e.g. asquare core or the like. In this configuration, two separate and unmixedairstreams are disposed at a 90° angle. Thus, a hot airflow (one arrowbeing designated by the reference number 1) is shown as crossing a pairof faces (both generally designated by the reference numeral 2) whilethe cold airflow (one arrow being designated by the reference number 4)is shown as crossing the other pair of faces (both generally designatedby the reference numeral 6). This configuration is very compact, butefficiency is theoretically limited.

FIG. 2 is illustrative of air flow through a counter flow core. In thisconfiguration, two separate and unmixed airstreams are disposed at a180° angle. Thus, a hot airflow (one arrow being designated by thereference number 8) is shown as crossing a pair of faces (both generallydesignated by the reference numeral 10) while the cold airflow (onearrow being designated by the reference number 12) is shown as crossingthe other pair of faces (both generally designated by the referencenumeral 14). This arrangement is the best on the efficiency side, butmore space is required. This is caused by the fact that two differentairflows cannot get into the core by opposed faces. An inlet/exhaustregion is required at each end of the core to separate hot and coldairflows.

Turning now to FIGS. 3 to 6, for the purpose of illustration thestackable spacer shown in FIGS. 3 to 6 has a frame member of somewhatexaggerated proportions in relation to the frame members shown withrespect to the spacers illustrated in FIGS. 7, 13 and 14; as may beappreciated in the latter figures the frame members have a stick likeaspect, i.e. a relatively thin aspect. The stackable spacer may beincorporated into an energy recovery core as shall be described below.

Referring to FIG. 3, the spacer 15 comprises a peripheral frame member16 of square configuration. The frame member 16 also has a first majorside (generally designated by the reference numeral 18) and an opposedsecond major side (generally designated by the reference numeral 20).The peripheral frame member 16 extends about and defines a framed coreopening 22, i.e. the frame member 16 is disposed about the periphery ofthe framed core opening 22. In other words the framed core opening 22extends from one major side 18 to the other major side 20 of the framemember 16. The peripheral frame member 16 comprises a pair of sideopening components 23 and a pair of side wall components 24. Each sideopening component 23 comprises a first element 26 and a second element28 associated with a respective major side of the frame member 16. Thusthe first elements 26 are associated with the major side designated bythe reference numeral 18 and the second elements 28 are associated withthe major side designated by the reference numeral 20. These first andsecond elements (26 and 28) are spaced apart so as to define a framedside opening 30. Each framed side opening 30 is in fluid (i.e. air)communication with the framed core opening 22, i.e. air may pass throughone of the framed side openings 26 into the framed core opening 22 andthen through the other framed side opening 26 as illustrated by arrow32. Each side wall component 24 (i.e. imperforate wall members)respectively interconnects the side opening components, i.e. each pairof the shown first and second elements 26 and 28 is connected to both ofthe side wall components 24.

On each major side of the frame member 16, the frame member 16 has aperipheral square ring engagement surface. The engagement surfaceassociated with the major side 18 as seen, has a portion thereof definedby each of the side wall components 24 and the first elements 26;similarly for the square ring surface associated with the other oppositemajor side 20 (hidden from view) has a portion thereof defined by eachof the side wall components 24 and the second elements 28. Although eachportion of the engagement surface on major side 18 is shown with anessentially flat engagement surface, the surfaces may alternatively takeon any other suitable aspect. They may for example take on a tongue andmortise aspect as discussed herein. In any event, as shall be furtherdiscussed below, the opposed engagement surfaces are both configured forengaging in sandwich fashion an air to air energy transfer sheetextending across the framed core opening 22. The engagement may, forexample, be facilitated either through the use of a suitable adhesivematerial or by any suitable means for urging the spacers together in amechanical pinching or clamping action about the exchanger sheet; theengagement is advantageously such that the energy transfer sheet may actas a kind of gasket so as to provide an air tight joint between adjacentengagement surfaces. If an adhesive is used it may be applied betweenone or both of the square ring engagement surfaces and a sandwichedenergy transfer sheet.

Thus turning to FIG. 4, this figure shows a pair of the example spacersas shown in FIG. 3 in the process of being associated with an air to airenergy transfer sheet 34 (e.g. paper). As may be understood the squareframe member 16 of FIG. 3 is configured, such that in the view shown inFIG. 4, the first or top such spacer 36 may be oriented 90 degrees inits plane with respect to the lower like spacer 38 and be stacked (i.e.disposed), major side to major side, on top of the second such spacer 16b with the air to air energy transfer sheet 34 disposed therebetween. Asmay be understood the energy transfer sheet 34 extends across the framedcore openings 22 and its peripheral edge may be sandwiched between theframe members 16 of the first and second spacers 36 and 38. With theenergy transfer sheet sandwiched between the frame members 16, the threepart combination defines a pair of transversely oriented air (channelsor) paths on opposite sides of the energy transfer sheet; each air pathextends from one respective framed side opening 30 through the framedcore opening 22 to the other respective framed side opening 30 of arespective spacer in the direction of the arrows 40 and 42. The energytransfer sheet 34 may be of any suitable (known) material able tofacilitate sensible heat transfer and if so desired the transfer ofhumidity (i.e. water vapor) as well; in other words the energy transfersheet 34 may be able to facilitate the transfer of latent heat as wellas sensible heat. The reference to a “energy transfer sheet” is ofcourse, as mentioned above to be understood herein to be a reference toa sheet or the like which is non-permeable to air so as to avoid mixingof air on opposite sides of the sheet.

Turning to FIG. 5, this figure illustrates an energy recovery coreassembled together using a plurality of suitably oriented spacers asshown in FIG. 3 and a plurality of energy transfer sheets 34 as shown inFIG. 4. As may be appreciated air flow through the core may occur in thedirection of the two arrows 44 and 46, the arrows respectivelyillustrating a first air path and a second air path through the core,i.e. through respective framed side openings 30. As also may beappreciated, the framed side openings 30 of alternating frame memberseach respectively define a respective element of the air inlet and airoutlet of the first air path and the framed side openings of the otheralternating frame members each respectively defining a respectiveelement of the air inlet and air outlet of the second air path.

The core as shown in FIG. 5 may be completed by covering the exposed topand bottom spacer frame core openings by suitable end cap sheets. Thetop and bottom cap sheets or plates may as mentioned above be maintainedin place by adhesive bonding to appropriate engagement surfaces or bysuitable mechanical clamping (not shown) as is known in the art inrelation to such multi-element cores; see for example the prior art asshown in U.S. Pat. No. 5,832,993 (FIG. 1 thereof) as well as FIG. 6thereof. Please also see FIG. 11 a for a further example of suchmechanical structure.

As shown in FIG. 6, an energy recovery core assembled as shown in FIG. 5may be incorporated into an air to air energy recovery system. Thesystem is shown schematically in cross section. The system has an upperpanel wall 48, a lower panel wall 49, and an intermediate partition wall50 disposed intermediate between the upper and lower panels walls 48 and49. The upper and lower panel walls 48 and 49 as well as the partitionwall 50 together define upper and lower air paths. The heat-exchangecore 52 is positioned between the upper and lower panel walls 48 and 49,across the partition wall 50 transversely to the upper and lower airpaths so as to divert fresh air (arrows 54) from the lower path to theupper path (arrows 56) and exhaust air (arrows 58) from the lower airpath to the upper air path (arrows 60). Thus cold exterior fresh airflowing through the lower air path may be diverted (pushed or pulled bya fan) through the heat-exchange core into the upper path for ultimateintroduction into an enclosure whereas warm stale interior air drawnfrom the interior of the enclosure into the lower air path may bediverted through the core to the upper air path for ultimate expulsioninto the atmosphere outside of the enclosure. It is to be understoodthat this separate cross over flow of these air streams through the corebring brings about an energy transfer from the warm to the cold airthrough the energy transfer sheets.

The fresh air introduced into the enclosure and the air discharged fromthe enclosure room flow through respective air passages or paths of theenergy recovery core, perpendicularly to each other, the perpendicularair paths being defined by the alternately stacked spacers components asdescribed above. Energy is transferred between the air introduced intothe enclosure and the air discharged from the enclosure while they areflowing through respective air path or passages of the energy recoverycore.

As mentioned above, a spacer may be configured to have (cooperating)tongue and mortise interlock aspects. Thus, for example, referring backto FIG. 3, the spacer illustrated may have (cooperating) tongue andmortise interlock aspects. In this case the frame member 16 on the firstmajor side 18 of the spacer may comprise one or more interlock members(not shown) selected from the group of consisting of a tongue interlockmember (e.g. male projection) and a mortise interlock member (e.g.female groove). Similarly, the frame member 16 on the second major side20 of the spacer may comprise one or more interlock members (not shown)also selected from the group consisting of a tongue interlock member(e.g. male projection) and a mortise interlock member (e.g. femalegroove). It must however, be borne in mind that the selection anddisposition of an interlock member for the first and second major sidesof the spacer must be made on the basis that two like spacers (as shownin FIG. 4) are to be able to be stacked one on the other such that onelike spacer may be oriented 90 degrees in its plane (as shown in FIG. 4)relative to the other like spacer. Such choice must at the same time bemade on the basis that if the first major side of a spacer has a tongueinterlock member, the second major side must have a correspondingcooperating mortise interlock member appropriately disposed andconfigured so as to allow the above mentioned orientation between likespacers and such that the tongue interlock member of one like spacer mayregister with the mortise interlock membert of the other like spacer soas to sandwich the exchanger sheet therebetween.

Thus, for example, referring back to FIG. 3, the portion of theengagement surfaces on each of the major sides 18 and 20 of the spaceras respectively defined by each first and second elements 26 and 28 ofeach side opening component 23 may take on a tongue aspect (e.g. maleprojection(s)). In other word, each first side opening component 23 maycomprise a first tongue interlock element and a second tongue interlockelement, the first and second tongue interlock elements each beingdisposed on a respective major side of the spacer and being spaced apartso as to define a framed side opening. On the other hand the portion ofthe engagement surfaces on each of the major sides 18 and 20 of thespacer as respectively defined by each side wall component 24 may, oneach major side of the frame member, take on a corresponding mortiseaspect (e.g. female groove(s)). In other words each second side wallcomponent 24 may comprise a first mortise interlock element and a secondmortise interlock element, the first and second mortise interlockelements each being disposed on a respective major side of the spacer.The tongue aspect and mortise aspects are of course disposed andconfigured to cooperate (i.e. have corresponding configurations orshapes) such that one of two adjacently stacked, like spacers, may beoriented 90 degrees in its plane relative to the other like spacer suchthat a tongue aspect(s) thereof may register with a mortise aspect(s) ofthe other spacer so as to sandwich the exchanger sheet therebetween.

Although the frame member shown in FIG. 3 is square it could for examplebe modified to have a rounded or circular aspect, i.e. the straightsides may be curved.

Referring to FIG. 7, this figure shows another example spacer which isprovided with tongue and mortise aspects. The illustrated spacerprovides an air path configuration which is a hybrid configuration ofthose shown in FIGS. 1 and 2; i.e. the configuration is a mix betweenthe cross flow and said counter flow configurations and is sometimesreferred to herein as the counter-cross flow. The configurationnevertheless provides for transversely oriented air flow paths over atleast a portion of the air flow through a core exploiting suchconfiguration; see FIG. 12.

Thus the stackable energy transfer core spacer shown in FIG. 7 comprisesa peripheral tongue and mortise frame member designated generally by thereference number 64. The frame member 64 has a first major side (shownin FIG. 7 a) and an opposed second major side (shown in FIG. 7 b). Theframe member 64 comprises a pair of side opening components 66 each ofwhich defines a respective framed side opening 68 (see also FIG. 10) andwhich shall be described in more detail below. As in the case of thespacer embodiment illustrated in FIG. 3 the frame member 64 comprises apair of side wall components (i.e. imperforate wall members). Each ofthe side wall components respectively interconnects the side openingcomponents 64. However for the spacer embodiment shown in FIG. 7 eachside wall component comprises two side wall elements 70 and 80 whichgive the illustrated spacer embodiment an hexagonal like shape whenviewed in plan view as shown in FIGS. 7, 7 a and 7 b.

The frame member 64 extends about a framed core opening 82. A number ofadditional elements are disposed in the framed core opening 82, namely aplurality of air guide or rib elements (one such rib element begindesignated by the reference numeral 84) which as shown take the form of“S” shaped air guiding members. The end tip of each rib guiding elementis also rounded to minimize pressure drop. Furthermore, to increase thestiffness of the spacer, three stiffening members or elements 86, 88 and90 are also disposed in the framed core opening 82; these stiffeningmembers 86, 88 and 90, as seen, extend across the framed core opening 82and have ends connected to the frame member 64. The stiffening members86, 88 and 90 are also connected to the bottoms of the air guide or ribelements to provide support and stiffness thereto. The stiffeningmembers 86, 88 and 90 are relatively thin as compared to the height ofthe air guide or rib elements so as to not block off the air channelsultimately definable by the air guide or rib elements (see for examplethe view of the spacer as seen in FIGS. 7 b and 10).

Referring back to FIG. 7, the stiffening members 86 and 88 are sodisposed as to define or form closed triangular structures withrespective to portions of the frame member; these triangular structuresor zones are indicated in outline generally by the dashed triangles 92and 94.

As well as being connected to the stiffening members 86 and 88 half ofthe air guide or rib elements are connected at their respective ends tothe side opening components 66 whereas the remaining half are connectedat their respective ends to the stiffening members 86 and 88. In thismanner the above mentioned triangular zones 92 and 94 also defineadjacent to the framed side openings 68 of the side opening components66 two low restriction zones. These low restriction zones have 50% lessguiding members to reduce the amount of friction caused by the presenceof the air guide or rib elements (e.g. plastic vanes).

Referring to FIGS. 7 and 10 the side opening components 66 comprisetongue members which are slightly shifted instead of being aligned.Therefore, corresponding mortise members shown herein as grooves need tobe shifted to ensure tongue & groove fit with the previous and the next(e.g plastic) spacer in an energy recovery core stack. This type oftongue/mortise structure is advantageous in that it avoids expensivemold tooling (with side action mechanisms).

Thus each first side opening component 66 comprises a first tongue(interlock) element designated respectively 96 as well as an inwardlyoffset second tongue (interlock) element designated respectively 98. Asmay be seen the first and second tongue elements 96 and 98 are onopposite major sides of the frame member 64. As may be seen the inwardlyoffset second tongue interlock element 98 of one said first side openingcomponents 66 is disposed on one major side and the inwardly offsetsecond tongue interlock element 98 of the other of said first sideopening components 66 is disposed on the other opposite major side.

Each pair of first and second tongue elements as may be appreciated arespaced apart so as to define the framed side opening 68, each framedside opening 68 being in fluid (i.e. air) communication with said framedcore opening 82, i.e. in fluid (i.e. air) communication with thechannels or paths defined by the air guide or rib elements 84.

As mention above each second side wall component comprises two side wallelements 70 and 80.

The side wall elements designated 70 each comprise a first mortiseelement 100 (i.e. a longitudinally extending groove) and an inwardlyoffset second mortise element 102 (i.e. a longitudinally extendinggroove) which are disposed on a respective opposite major sides of theframe member 64; see as well FIGS. 7 a and 7 b. The inwardly offsetsecond mortise element 102 of one said side wall elements 70 is disposedon one of the major sides while the inwardly offset second mortiseelement 102 of the other of said second side wall elements 70 isdisposed on the opposite major side of the frame member.

The first and second tongue elements 96 and 98 of the each first sideopening component 66 is configured and disposed to be able to registerwith a respective first and second mortise element 100 and 102 of arespective side wall element 70 of an adjacent like spacer.

On the other hand the second wall elements designated 80 each comprisean first tongue element 104 (i.e. a longitudinally extending projection)aligned with a first mortise element 106 (i.e. a longitudinallyextending groove) which are disposed on a respective opposite majorsides of the frame member. The first tongue element 104 of one of saidsecond side wall elements 80 is disposed on one of the major sides whilethe first tongue element 104 of the other of said second side wallelements 80 is disposed on the opposite major side of the frame member.The first tongue elements 104 are configured and disposed to be able toregister with a respective first mortise element 106 of a respectiveside wall element 80 of an adjacent like spacer

FIG. 8 illustrates in schematic fashion how the offset elements of thetongue/mortise means are able to register with each other to sandwich anair to air energy transfer sheet 110 therebetween i.e. the variouselements are configured to matingly conform with each other.

FIG. 9 illustrates the form of a heat transfer or exchanger sheetexploitable with the spacer shown in FIG. 7. Such energy transfer mediaare known and can be made from numerous different materials, includingspecially treated paper sheets, fiberglass reinforced sheets or anyother type suitable for the application. This leads to a very flexiblemanufacturing process.

FIG. 10 is a schematic perspective view of a plurality of the examplespacers as shown in FIG. 7 in the process of being associated with aplurality of air to air energy exchanger sheets 110 (e.g. paper) asshown in FIG. 9. The frame member of FIG. 7 is configured such that onespacer may be stacked on an underlying spacer by first being orientedwith respect to the underlying like spacer by being flipped over 180degrees around the central longitudinal axis 112 passing through thecentral stiffening member 90 (see for example FIG. 7). In other words inorder to be able to use the same spacer all across a heat recovery thecore, the said like spacers need each to be flipped during assembly.Referring to FIG. 10, this means that one spacer 114 is mounted facingup and the underlying adjacent spacer 116 is mounted facing down, and soon and so forth. To ensure a good fit between membrane and spacers, themembrane is asymmetrical (see FIG. 9); thus each new additional energytransfer sheet in the assembly also has to be rotated by 180° (about thelongitudinal axis passing through the center of the opposed major facesof the sheet) as compared to the immediately lower and upper sheets.

Thus as may be appreciated from FIG. 10 a spacer of FIG. 7 is stacked,major side to major side, on top of a second such spacer with an air toair energy exchanger sheet extending across the framed core openings andsandwiched between the frame members of said first and second spacerssuch that second offset interlock tongue elements register in respectiveoffset second mortise elements and first interlock tongue elementsregister in respective first mortise elements so as to define a pair oftransverse air (channels or) paths on opposite sides of the energytransfer sheet (see FIG. 12). The result is a core assembly as shown inFIG. 11.

The various elements of the core assembly shown in FIG. 11 may also besecured by using glue, e.g. by glueing the engagement surfaces of theframe members to the energy transfer sheets sandwiched therebetween.Alternatively, they may be secured by using suitably configuredsnap/lock elements (see FIGS. 18 and 19) disposed on the (e.g. plastic)spacers. Ultrasonic welding technique can also be used, even if snaps orglue is already used. It is advantageous to firmly hold the energytransfer media in place, especially when the said media reacts toenvironment conditions which may lead to expansion/contractionphenomenon due to heat and/or humidity variation.

Referring to FIG. 11 a, this figure illustrates an example frameclamping assembly for mechanically maintaining in place the elements ofthe core assembly shown in FIG. 11. The frame clamping assembly has apair of end plates or caps 120 for covering the bottom and top of thecore assembly of FIG. 11. The frame clamping assembly also is providedwith nut/bolt type fasteners (indicated generally by the referencenumeral 122) which may take any form provided that they can bemanipulated to urge the caps 120 towards each other so as to clampelements of the core assembly in place. Thus a nut/bolt type fasteners122 may comprise a post member 122 a fixed at one end to the lower cap120 and provided with a screw threaded opening at the other end thereoffor engaging the threaded shaft of a bolt 122 b, the head of which maybemade to press down on the upper cap 120. The post members 122 a may besized so as to be able to be seated in the longitudinally extendingnotches 128 (see FIG. 11).

Referring back to FIG. 12, this figure shows an energy transfer corestage comprising two superimposed spacers having the configuration shownin FIG. 7 (with an intermediate energy transfer sheet normally disposedtherebetween not shown for illustration purposes) and the resultingairflow paths which would be provided on opposite sides of the energytransfer sheet; the paths being represented by the arrows 130 and 132.The center portion of core stage is arranged in a way that the anglebetween the hot and cold airflows is 143°. This configuration results ina great value package, allowing good efficiency in a very compactarrangement.

Turning to FIG. 13, 13 a, 13 b, 13 c and 13 d these figures areillustrative of an alternative spacer structure based on the spacer coreshown in FIG. 3 and common elements will have common reference numerals.Thus the spacer is of square configuration. The spacer however also hasan element of the spacer shown in FIG. 7. Thus the spacer has aplurality of parallel of air guide or rib elements (one of which isdesignated by the reference number 140) which serve the same purpose asthose for the spacer in FIG. 7, namely to guide an air flow from oneframed side opening to the other framed side opening. This alternatespacer also includes snap lock connector elements disposed on each majorside e.g. female lock members disposed at the corners of the undersideof the spacer and cooperating male lock members disposed on the upperside of the spacer; these lock members may take any suitable (known)form.

Referring top FIGS. 14, 15, 15 a, 16, and 16 a, these figures illustratea further alternate spacer configuration which is also based on thesquare spacer structure shown in FIG. 3 and is associated with a squareenergy transfer sheet 144. However, this spacer variant includes otheraspects of the spacer structure shown in respect to the spacerillustrated in FIG. 7. Thus the spacer 146 has a plurality of parallelof air guide or rib elements (one of which for each spacer shown isdesignated by the reference numeral 148) which serve the same purpose asthose for the spacer in FIG. 7, namely to guide an air flow from oneframed side opening 30 to the other framed side opening 30. The spaceralso includes tongue/mortise elements. These elements may be gleanedfrom the enlarged views in FIGS. 15 a and 16 a. Each of the two opposedside opening components has an upper tongue element 150 and a lowermortise element 152 which are spaced apart to define a framed sideopening 30. Each of the two opposed side wall components has an uppertongue element 154 and a lower mortise element 156. These tongue/mortiseelements are as seen configured such that the spacer of FIG. 12 can besequentially rotated 90 degrees about the axis 160 (see FIG. 14) so asto form the assembled core have air cross flow structure in thedirection of the arrows shown with respect to FIG. 15.

For those spacers as shown in FIGS. 7, 13 and 14 which comprise one ormore rib air guide elements disposed in the framed core opening, saidrib air guide elements being connected to the frame member, the rib airguide elements may merely rest up against the adjacent air to air heattransfer sheet, i.e. they are not attached to nor integral with the airto air heat transfer sheet.

Referring to FIGS. 17 and 18, as mentioned above frame members of a coremay be provided with snap lock connector elements. FIG. 17 illustrates amale and female approach to such connectors, i.e. a male element 162 isconfigured and disposed so as to be able to snap lock with theappropriately configured female element 164. FIG. 18 shows a snap hooktype mechanism wherein respective resilient hook members 166 of adjacentspacers are able to cam over each other and then inter-hook each other.

Thus for example with respect to a snap lock means as shown in FIG. 17,a snap lock connector assembly may for example comprise an elongate malemember snap lockable with a female member. One of such snap lock membersmay be associated with one major side of a frame member and the otherbeing associated with the other side of the frame member. The elongatemale member may have a generally bulbous outer end and a longitudinallyextending intermediate portion attached to the frame member and being ofsmaller transverse cross-sectional dimensions than said bulbous outerend. The female member may also be connected to the frame member (on theother side thereof) and have an elongated, internal passageway having anopening of slightly smaller dimensions than the bulbous outer end of themale member. The female member may also have a longitudinally extendinggenerally non-flexible portion of slightly larger inner dimensions thansaid bulbous outer end of said male member. One of said male and femalemembers may comprise flexible, resilient material. The snap lock iseffected by forcing the male bulbous outer end into the internalpassageway of the female member; once inside the internal passageway thesmaller opening of the female member will tend to lock the memberstogether.

1. A stackable energy transfer core spacer comprising a peripheral frame member, said peripheral frame member extending about and defining a framed core opening, said peripheral frame member having a pair of opposed major sides, said peripheral frame member comprising a pair of side opening components and a pair of side wall components, each side opening component comprising a framed side opening in air communication with said framed core opening, each side wall component respectively interconnecting said side opening components, said spacer being configured such that said spacer may be oriented and stacked, major side to major side, on top of a second like spacer, with an intermediate air to air energy transfer sheet extending across the framed core openings and being sandwiched between the frame members of both spacers so that the spacers and the energy transfer sheet define a pair of transversely oriented air paths on opposite sides of the energy transfer sheet, each air path extending from one respective framed side opening through a respective framed core opening to the other respective framed side opening of a respective spacer.
 2. A stackable energy transfer core spacer as defined in claim 1 wherein said peripheral frame member, on each major side thereof, comprises an inter-registrable tongue/mortise interlock element.
 3. A stackable energy transfer core spacer as defined in claim 2 wherein said frame member is configured such that when the air to air energy transfer sheet is sandwiched between said frame member and the frame member of said second like spacer, the air to air energy transfer sheet is sandwiched between tongue/mortise interlock elements of said frame member and the frame member of said second like spacer.
 4. A stackable heat transfer core spacer as defined in claim 1 having a square configuration.
 5. A stackable heat transfer core spacer as defined in claim 1 having a hexagonal configuration.
 6. A stackable energy transfer core spacer as defined in claim 1 wherein the spacer comprises one or more rib air guide elements disposed in the framed core opening, said rib air guide elements being connected to the frame member.
 7. An air to air energy recovery core having a first air path and a separate second air path, each air path having a respective air inlet and a respective air outlet, said core comprising a stack of one or more successive heat transfer stages, each such stage comprising an energy transfer sheet having opposed major faces and a pair of spacers engaging opposite major faces of the sheet, each of said spacers being a spacer as defined in claim 1, said spacers being oriented and disposed relative to each other so that the spacers and the energy transfer sheet define a pair of transversely oriented air paths on opposite sides of the energy transfer sheet, each air path extending from one respective framed side opening through a respective framed core opening to the other respective framed side opening of a respective spacer, the framed side openings of one frame member each respectively defining a respective element of the air inlet and air outlet of the first air path and the framed side openings of the other frame member each respectively defining a respective element of the air inlet and air outlet of the second air path. 